1. Field of the Invention
The present invention relates to a retention mechanism for securing an electronic assembly to a motherboard that has studs provided.
2. Background Information
FIG. 1 shows a product marketed by Intel Corporation, the assignee of this application, which is referred to as a single edge contact cartridge (SECC). The Intel SECC includes a microprocessor which is assembled into a package 1 that is mounted to a substrate 2. The SECC may also have other integrated circuit packages 3 which contain static random access memory (SRAM) integrated circuits.
One edge of the substrate 2 has a plurality of conductive pads 4 which can be inserted into an electrical connector 5. The electrical connector 5 can be mounted to a printed circuit board 6 such as the motherboard of a computer. The pads 4 and connector 5 electrically couple the substrate 2 to the circuit board 6.
The substrate 2 and integrated circuit packages 1 and 3 are enclosed by a cover 7 and a thermal plate 8. The cover 7, plate 8 and substrate 2 provide an electronic cartridge which can be plugged into a computer motherboard 6.
The electrical system shown in FIG. 1 can sustain external shock and vibration loads. Such loads may produce intermittent separation between the pads 4 and the connector 5. Intermittent separation between the pads 4 and connector 5 may create electrical xe2x80x9copens.xe2x80x9d The system is provided with a retention mechanism 9 to secure the substrate 2 to the connector 5 and prevent contact separation under shock and vibration loads.
The retention mechanism 9 includes a pair of posts 10 that are mounted to the circuit board 6. Each post 10 includes an aperture 11 which receives a latch 12 that extends from the cover 7 of the cartridge. When inserted into the aperture 11 each latch 12 prevents the substrate 2 from being pulled out of the connector 5. The substrate 2 can be unplugged from the connector 5 by pressing a pair of latch levers 13 and pulling the cartridge away from the board 6. Pressing the levers 13 moves the latches 12 out of the apertures 11 of the posts 10.
The integrated circuits generate heat which must be removed from the circuits. The thermal plate 8 is thermally coupled to the integrated circuit package 1 of the SECC to provide a thermal path for the heat generated by the microprocessor. A heat sink 14 may be mounted to the thermal plate 8 to further facilitate the removal of the heat.
The heat sink 14 is typically constructed from a thermally conductive material such as aluminum or copper. Metal heat sinks 14 have a weight which increases the magnitude of loads on the cartridge, particularly when the system is subjected to shock or vibration.
The Intel SECC includes a heat sink support assembly 15 that is mounted to the printed circuit board 6 and supports the heat sink 14. The support assembly 15 includes a support bar 16 that is inserted into holes of the circuit board 6. The assembly 15 also includes a tie bar 17 that is inserted into a groove 18 of the heat sink 14 and snapped onto posts 19 of the support bar 16.
It is desirable to reduce the number of parts in an electrical assembly to reduce the complexity and cost of mass producing the product. It would therefore be desirable to provide a single retention mechanism which secures the substrate to the connector and supports a heat sink of the electronic assembly. Additionally, it would be desirable to eliminate the through holes required to install the support bar of the SECC. The through holes occupy valuable routing space on the printed circuit board.
One embodiment of the present invention is a retention mechanism for an electronic assembly which has a substrate and a heat sink. The assembly includes a heat sink slot that receives the heat sink, and a substrate slot that receives the substrate.